on 12-28-2019 08:20 PM
I'd assume that you don't have the address for the eBay IDs for the seller or the buyer?
Just postal addresses?
Is there by chance a telephone number?
If there is use it to notify the seller (or buyer) what has happened and that you will be calling PB/GSP about this.
Don't make any promises (yet) that will cost you money unless you are really working on your karma.
Ask the member to contact the other party to the transaction, just so everyone will know what is happening.
Then contact Pitney Bowes, which runs the Global Shipping Program.
This is the only contact point I have for them, but you may be able to find something more human on the website.
https://parceltracking.pb.com/app/#/dashboard/
This might work on Dec 31, but otherwise it would be best to wait until January 2.
Best wishes for a happy and prosperous New Year.